This is not required if your frontend and your API run in the same domain or if you set the Access-Control-* headers properly. In this case just use an XMLHttpRequest and don't use this middleware at all. Reference: MDN - HTML5Rocks - SO

There is a way to read a JSONP response after sending a POST request (form) in the browser. The solution is to set an iframe as target of the form (could be hidden). The iframe will load your response page, in this case plain HTML with a script tag and will call your callback using parent.callbackname(data).

This is an old snippet using mootools that creates a form, an iframe, and posts your request. Then dispose everything after executing your callback.
You can easily port it to jQuery.

The test suite is written on top of mochajs/mocha and it took hours of hard work. Please use the tests to check if your contribution is breaking some part of the library and add new tests for each new feature.

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